Ceramics, such as silicon nitride and silicon carbides, are becoming more widely used by industry in parts that previously were typically made of metals. For example, industry now uses ceramics in the manufacture of bearing balls. Because balls in such bearings are subject to high dynamic stress, and due to the inherent brittleness of ceramics, it is important to inspect each ball for defects, including surface and subsurface cracks or deformities. Stress concentration caused by the existence of surface or subsurface cracks can lead to the total mechanical failure of parts.
It is highly desirable to quickly perform a cursory inspection of a test object for defects. If by that cursory inspection it is determined that the test object is not free of defects, a more detailed inspection of the test object may be performed to determine the type and extent of the defect. In a patent granted to the inventor of the present case, U.S. Pat. No., 4,995,259, therein described is an acoustic microscope surface inspection system for providing detailed defect analysis of a test object.